CN113544457A

CN113544457A - Propeller fan

Info

Publication number: CN113544457A
Application number: CN202080019290.8A
Authority: CN
Inventors: 岛野太贵; 高冈亮; 渡边政利; 前间庆成; 仲田升平; 冈孝多郎
Original assignee: Fujitsu General Ltd
Current assignee: Fujitsu General Ltd
Priority date: 2019-03-28
Filing date: 2020-03-25
Publication date: 2021-10-22
Anticipated expiration: 2040-03-25
Also published as: CN113544457B; US20220128319A1; JP7188564B2; EP3951308A4; US11828544B2; JPWO2020196592A1; AU2020248511B2; EP3951308A1; WO2020196592A1; AU2020248511A1

Abstract

The heat exchanger (5) comprises: a plurality of flat tubes stacked in a direction perpendicular to a flow direction of the refrigerant; the heat exchanger comprises a plurality of fins (111) which are provided with a first flat pipe in the flat pipes, a second flat pipe adjacent to the first flat pipe, a first flat pipe insertion part (113A) for inserting the first flat pipe, and a second flat pipe insertion part (113B) for inserting the second flat pipe. The first fin (111) is formed with cut-and-raised pieces (114) at the inner peripheral edge of the first flat tube insertion section (113A) for spacing a fin pitch (P) between the first fin (111) and an adjacent second fin (111). The cut-and-raised piece (114) has a raised portion having the same length as the fin pitch (P) and a folded portion folded back at the tip of the raised portion and brought into contact with the second fin (111).

Description

Propeller fan

Technical Field

The present invention relates to heat exchangers.

Background

A heat exchanger having the following structure is known: flat tubes (heat transfer tubes) having a plurality of flow path holes therein are connected at both ends thereof to a pair of headers, and refrigerant is branched into the flat tubes in the headers. The flat tubes are stacked in a direction perpendicular to a flow direction of the refrigerant. Then, a plurality of fins are arranged between a pair of headers connected to both ends of the flat tubes, and the plurality of fins are connected to the respective flat tubes. In this heat exchanger, the refrigerant flowing through the flow passage holes in the flat tubes exchanges heat with air flowing between the plurality of fins through the plurality of fins.

For example, as shown in fig. 5, a fin 111A of the heat exchanger 5A has a flat tube insertion portion 113A formed by cutting out a part of a ventilation portion 112A. Flat tubes 11 are inserted into flat tube insertion portions 113A of fins 111A (heat exchanger 5A has a plurality of fins 111A arranged in a direction perpendicular to the paper of fig. 5). A plurality of flow passage holes 10A through which the refrigerant flows are provided in the flat tube 11.

Here, in order to secure the fin pitch P1 between the fins 111A adjacent to each other, as shown in fig. 6, there is known a structure in which: a part of the fins 111A is used as the cut-and-raised piece 114A, and the fin pitch P1 is ensured by bringing the cut-and-raised piece 114A into contact with the adjacent fin 111A. The cut-and-raised piece 114A has: a rising portion 115A rising from the fin 111A, and a folded portion 116A folding back the tip of the rising portion 115A. The notch portion formed on the fin 111A by forming the cut-and-raised piece 114A and having a length of W1 is referred to as a notch residual portion C1.

As a portion corresponding to the notch residual portion C1, that is, a position where the cut-and-raised piece 114A is formed, as shown in fig. 7, there is an example where the cut-and-raised piece 114A is formed in the ventilation portion 112A of the fin 111A. However, the case of this example is not preferable from the viewpoint of ventilation resistance of air flowing between the fins 111A, or drainage of condensed water adhering to the surfaces of the fins 111A. On the other hand, as shown in fig. 8, there is an example in which cut-and-raised pieces 114A are formed in the flat tube insertion portions 113A of the fins 111A. In this example, since the cut-and-raised pieces 114A are arranged along the longitudinal direction of the flat tubes 11 at positions in contact with the flat tubes 11, ventilation between the fins 111A is not hindered, and drainage of condensed water is not reduced (see, for example, patent document 1). Normally, the flat tube insertion portions 113A are formed by cutting out a part of the fins 111A by press working or the like (see fig. 9, black portions in fig. 9 are removed). However, in patent document 1, at least a part of the flat tube insertion portion 113A is not removed to leave as a notched residual portion C1, and the notched residual portion C1 is bent in a direction perpendicular to the ventilation portion 112A to serve as a cut-and-raised piece 114A (see fig. 8).

However, in the structure of patent document 1, the length of the notch residual portion C1, that is, the cut-and-raised piece 114A bent and raised with respect to the vent portion 112A, is limited to the width range of the flat tube insertion portion 113A corresponding to the thickness of the flat tube 11. Therefore, patent document 1 has the following problems: when the thickness of the flat tube 11 is smaller than the required fin pitch P1, the notch residual portion C1 cannot be sufficiently ensured, and therefore the cut-and-raised piece 114A cannot reach the adjacent fin 111A, and the fin pitch P1 between the fins 111A adjacent to each other cannot be appropriately ensured.

Patent document 1: japanese patent laid-open publication No. 2017-198440

Disclosure of Invention

The present invention has been made in view of the above problems, and an object thereof is to provide a heat exchanger capable of ensuring a desired fin pitch regardless of the thickness of a flat tube.

The present application discloses a heat exchanger, one form of which is provided with: a plurality of flat tubes stacked in a direction perpendicular to a flow direction of the refrigerant; and a plurality of fins each having a first flat tube among the plurality of flat tubes, a second flat tube adjacent to the first flat tube, a first flat tube insertion portion into which the first flat tube is inserted, and a second flat tube insertion portion into which the second flat tube is inserted, wherein a first fin among the plurality of fins is formed with a cut-and-raised piece at an inner peripheral edge of the first flat tube insertion portion, the cut-and-raised piece being used to space a fin pitch between the first fin and the adjacent second fin, the cut-and-raised piece having a rising portion having the same length as the fin pitch, and a return portion that is returned at a front end of the rising portion and abuts against the second fin.

According to the present invention, a desired fin pitch can be ensured regardless of the thickness of the flat tube.

Drawings

Fig. 1 is a diagram illustrating a structure of an air conditioner to which a heat exchanger according to an embodiment is applied.

Fig. 2A is a plan view for explaining the heat exchanger according to the embodiment.

Fig. 2B is a front view for explaining the heat exchanger according to the embodiment.

Fig. 3 is a side view illustrating a fin of a heat exchanger according to an embodiment.

Fig. 4 is a cross-sectional view E-E in fig. 3 showing a fin of the heat exchanger according to the embodiment.

Fig. 5 is a view illustrating a flat tube insertion portion of a fin in a heat exchanger of the related art.

Fig. 6 is a view illustrating cut-and-raised pieces of fins in a heat exchanger of the related art.

Fig. 7 is a diagram showing an example in which cut-and-raised pieces of fins are provided in ventilation portions of the fins in a heat exchanger according to the related art.

Fig. 8 is a view showing an example in which cut-and-raised pieces of fins are provided in a flat tube insertion portion in a heat exchanger according to the related art.

Fig. 9 is a view showing a notch portion of a flat tube insertion portion in a heat exchanger of the related art.

Fig. 10 is a view illustrating a modification of the fin reinforcing portion in the fin of the heat exchanger according to the embodiment.

Fig. 11 is a view for explaining another modification of the fin reinforcing portion in the fin of the heat exchanger according to the embodiment.

Fig. 12 is a view illustrating a modification of the notch portion in the fin of the heat exchanger according to the embodiment.

Fig. 13 is a view for explaining another modification of the notch portion in the fin of the heat exchanger according to the embodiment.

Detailed Description

Detailed description of the preferred embodiments

Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as "embodiment") will be described in detail with reference to the drawings. In the description of the embodiments, the same elements are denoted by the same reference numerals.

Integral structure of air conditioner

Fig. 1 shows a configuration of an air conditioner 1 to which a heat exchanger 5 according to an embodiment of the present invention is applied. As shown in fig. 1, the air conditioner 1 includes an indoor unit 2 and an outdoor unit 3. The indoor unit 2 is provided with an indoor heat exchanger 4. The outdoor unit 3 includes a compressor 6, an expansion valve 7, a four-way valve 8, and the like, in addition to the outdoor heat exchanger 5.

During heating operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 6 of the outdoor unit 3 flows into the indoor heat exchanger 4 through the four-way valve 8. The refrigerant flows in the direction of the black arrows in fig. 1. During heating operation, the indoor heat exchanger 4 functions as a condenser, and the refrigerant that has exchanged heat with air condenses and liquefies. Thereafter, the high-pressure liquid refrigerant passes through the expansion valve 7 of the outdoor unit 3, is depressurized, becomes a low-temperature low-pressure gas-liquid two-phase refrigerant, and flows into the outdoor heat exchanger 5. The outdoor heat exchanger 5 functions as an evaporator, and vaporizes the refrigerant after exchanging heat with the outside air. Thereafter, the low-pressure gas refrigerant is sucked into the compressor 6 through the four-way valve 8.

During the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 6 of the outdoor unit 3 flows into the outdoor heat exchanger 5 through the four-way valve 8. The refrigerant flows in the direction of the white arrows in fig. 1. During the cooling operation, the outdoor heat exchanger 5 functions as a condenser, and condenses and liquefies the refrigerant that has exchanged heat with the outside air. Thereafter, the high-pressure liquid refrigerant passes through the expansion valve 7 of the outdoor unit 3, is decompressed, becomes a low-temperature low-pressure gas-liquid two-phase refrigerant, and flows into the indoor heat exchanger 4. The indoor heat exchanger 4 functions as an evaporator, and vaporizes the refrigerant that has exchanged heat with air. Thereafter, the low-pressure gas refrigerant is sucked into the compressor 6 through the four-way valve 8.

Heat exchanger

The heat exchanger of the present embodiment is applicable to the indoor heat exchanger 4 and the outdoor heat exchanger 5, but in the following description, it will be described as the heat exchanger 5 which functions as an evaporator during heating operation and is applicable to the outdoor unit 3. The heat exchanger 5 of the outdoor unit 3 may be used as a flat plate type as shown in fig. 1, or may be used as an L-shaped heat exchanger in fig. 1. In general, the L-shaped heat exchanger 5 can be obtained by bending the heat exchanger 5 formed in a flat plate shape. The specific manufacturing process is an assembly process for assembling the flat plate type heat exchanger 5 by a component coated with brazing filler metal on the surface; a brazing step of placing the assembled flat plate-type heat exchanger 5 in a furnace for brazing; and a bending step of bending the brazed flat plate heat exchanger 5 into an L-shape, thereby manufacturing the L-shaped heat exchanger 5. Next, a flat plate type heat exchanger 5 will be explained as the heat exchanger of the present invention.

Fig. 2A is a plan view for explaining the heat exchanger 5 according to the embodiment. Fig. 2B is a front view for explaining the heat exchanger 5 according to the embodiment. As shown in fig. 2A and 2B, the flat tubes 11 have a flat shape with respect to the vertical direction, are provided along the direction in which the refrigerant flows between the pair of headers 12 (the longitudinal direction of the flat tubes 11), and air flows along the width direction of the flat tubes 11. A plurality of flow path holes 10A through which the refrigerant flows in the longitudinal direction of the flat tubes 11 are formed in the flat tubes 11, and the flow path holes 10A are aligned in the air flow direction (the width direction of the flat tubes 11). The heat exchanger 5 includes: a plurality of flat tubes 11 arranged in the vertical direction (the direction perpendicular to the flow direction of the refrigerant) such that the wide surfaces of the side surfaces of the flat tubes 11 in the longitudinal direction of the flat tubes 11 face each other; a pair of left and right headers 12 connected to both ends of the flat tubes 11; and a plurality of fins 111 arranged in a direction intersecting flat tubes 11 and joined to each flat tube 11. Among two flat tubes 11 adjacent to each other in the vertical direction, the flat tube 11 on the upper side in the drawing may be referred to as a first flat tube 11A, and the flat tube 11 on the lower side in the drawing may be referred to as a second flat tube 11B, for the plurality of flat tubes 11. In the heat exchanger 5, refrigerant pipes (not shown) connected to other elements of the air conditioner 1 and through which the refrigerant flows are connected to the header 12.

The flat tubes 11 are arranged in parallel in the vertical direction with an interval S1 for allowing air to flow therebetween, and both ends of the flat tubes 11 are connected to the pair of headers 12. Specifically, in fig. 2B, the flat tubes 11 extending in the left-right direction are arranged at a predetermined interval S1 in the vertical direction for allowing air to flow therethrough, and both ends of each flat tube 11 are connected to the header 12.

The header 12 is formed in a cylindrical shape, and a refrigerant flow path (not shown) that either branches the refrigerant supplied to the heat exchanger 5 into each of the plurality of flat tubes 11 or merges the refrigerant flowing out from each of the plurality of flat tubes 11 is formed inside the header 12.

The fins 111 are formed in a flat plate shape, and are stacked in the longitudinal direction of the flat tubes 11 so as to intersect the flat tubes 11 when viewed from the front of the heat exchanger 5. The plurality of fins 111 are arranged side by side with a gap S1 for allowing air to flow therethrough. The plurality of fins 111 extending in the vertical direction are arranged at a predetermined fin pitch P with respect to the longitudinal direction of the flat tubes 11 (the horizontal direction in fig. 2B).

Main part of fin

Next, the main portions of the fin 111 of the heat exchanger 5 according to the present embodiment will be described with reference to fig. 3 and 4. In fig. 3 and 4, the vicinity of the flat tube insertion portion 113 of the fin 111 to be described later is shown in an enlarged manner, and the flat tube 11 is not shown. The cut-and-raised piece 114 of the present embodiment has: a standing portion 115, and a folded portion 116 for folding back the front end of the standing portion 115.

As shown in fig. 3, the fin 111 includes: a vent 112, a plurality of flat tube inserts 113, and a plurality of cut-and-raised tabs 114. The ventilation portion 112 is provided between the flat tube insertion portions 113. The flat tube insertion portions 113 are formed by cutting out a part of the fins 111 by press working or the like, but leave portions for forming a part of the cut-and-raised pieces 114 (notch residual portions C1). The cut-and-raised pieces 114 are formed of a portion corresponding to the cut-and-remaining portion C1 of the fin 111 and a portion corresponding to the cut-and-raised portion C2, and the cut-and-raised portion C2 is formed of a portion of the inner peripheral edge of the flat tube insertion portion 113 facing the inner peripheral edge where the cut-and-raised pieces 114 stand, on the side of the ventilation portion 112. Notch C2 is a through-portion continuous with flat tube insertion portion 113. Among two flat tube insertion portions 113 adjacent to each other in the vertical direction, the flat tube insertion portion 113 on the upper side in fig. 3 may be referred to as a first flat tube insertion portion 113A (corresponding to the first flat tube 11A) and the flat tube insertion portion 1131 on the lower side in fig. 3 may be referred to as a second flat tube insertion portion 113B (corresponding to the second flat tube 11B) among the plurality of flat tube insertion portions 113.

The cut-and-raised piece 114 is bent at a first edge 120 (an upper inner peripheral edge in fig. 3) of the flat tube insertion portion 113. The region C constituting the entirety of the cut-and-raised piece 114 means: the fin 111 has a portion corresponding to the notch residual portion C1 of the flat tube insertion portion 113 and a portion corresponding to the notch portion C2, and the notch portion C2 is formed by cutting a portion of the ventilation portion 112 on the second side 121 (lower inner peripheral edge in fig. 3) side facing the first side 120. The length of the rising portion 115 is the length in the rising direction of the rising portion 115 from the inner peripheral edge of the flat tube insertion portion 113, and is formed to be the same as the fin pitch P (see fig. 4). The length of the notch residual portion C1 is a length W1 from the first side 120 to the second side 121, and the length of the notch portion C2 is a length W2 from the second side 121 to the contour having the longest distance (the lower end of the arc-shaped notch portion C2). In other words, the length of the sum of the rising portion 115 and the folded portion 116 constituting the whole of the cut-and-raised piece 114 is the length W1 lengthened by the length W2.

In fig. 3, cut-and-raised piece 114 is provided on the upper inner peripheral edge of flat tube insertion portion 113 in fig. 3, i.e., first edge 120, but may of course be provided on the lower inner peripheral edge in fig. 3, i.e., second edge 121. That is, the cut-and-raised piece 114 may be formed to stand from the second side 121 of the flat tube insertion portion 113.

Fig. 4 shows a cross section of the cut-and-raised piece 114 in a state of being bent from the fin 111 and being cut and raised. Fig. 4 shows the relationship between the fin pitch P of the fins 111 adjacent to each other and the cut-and-raised pieces 114. The same applies to the upper fin 111 in fig. 4 as to the lower fin 111 in fig. 4. Note that, for convenience sake, in fig. 4 showing the configuration of the present embodiment, the notch portion C2 is shown as a part of the ventilation portion 112, compared with fig. 6 showing the conventional configuration. As shown in fig. 4, in the first fin 111a (the lower fin 111 in fig. 4), the cut-and-raised piece 114 having a portion corresponding to the notch residual portion C1 of the flat tube insertion portion 113 and a portion corresponding to the notch portion C2 on the ventilation portion 112 side in the flat tube insertion portion 113 is formed by bending the first side 120 (the inner peripheral edge on the right side in fig. 4) of the flat tube insertion portion 113.

In cut-and-raised piece 114A (see fig. 6) in the conventional structure described above, region C of fin 111A constituting cut-and-raised piece 114A coincides with a portion (length W1) corresponding to notch residual portion C1 of flat tube insertion portion 113A. Therefore, the fin pitch P1 in the conventional structure is limited to a range of a portion (length W1) corresponding to the notch residual portion C1. The portion (length W1) corresponding to the notch residual portion C1 substantially corresponds to the thickness of the flat tube 11. Therefore, when the required fin pitch P1 is larger than the thickness dimension of the flat tube 11, the length of the cut-and-raised piece 114A is insufficient only for the portion (length W1) corresponding to the notch residual portion C1.

In contrast, as shown in fig. 4, in the cut-and-raised piece 114 according to the present embodiment, the region C of the first fin 111a constituting the cut-and-raised piece 114 includes: the portion (length W1) corresponding to the notched residual portion C1 of the flat tube insertion portion 113 is added to the portion (length W2) corresponding to the notched portion C2 provided on the second side 121 side, which is a portion on the vent portion 112 side. Therefore, even if the required fin pitch P is larger than the thickness dimension of the flat tubes 11, the cut-and-raised pieces 114 can be cut and raised by adding the distance P2 to the fin pitch P1 corresponding to the thickness of the flat tubes 11, and the required fin pitch P can be secured.

Here, although the cut-and-raised piece 114 is not necessarily provided with the folded-back portion 116, in order to prevent crushing of the cut-and-raised piece 114 and further reliably ensure the fin pitch P, the cut-and-raised piece 114 is preferably in surface contact with the adjacent second fin 111b by the folded-back portion 116.

Fig. 3 and 4 do not show that the entire length of the portion (length W2) corresponding to the notch C2 corresponds to the folded portion 116. Length W2 of the portion corresponding to notch portion C2 may be appropriately set in accordance with the required fin pitch P and the thickness of flat tube 11, which is the portion corresponding to notch residual portion C1 of flat tube insertion portion 113 (length W1), and a portion corresponding to notch portion C2 may constitute a part of rising portion 115 and folded-back portion 116 in accordance with the required fin pitch P.

The portion corresponding to the notch residual portion C1 and the portion corresponding to the notch portion C2 are not limited to the illustrated shapes, and may have other shapes.

The fin reinforcing portion 117 will be described with reference to fig. 3. When it is necessary to increase the rigidity reduced by forming the notch portion C2, the fin 111 may further include a fin reinforcing portion 117 as shown in fig. 3.

The fin reinforcing portion 117 is provided in the vicinity of a notch portion C2 that is a part of a region C cut and raised as a part of the cut-and-raised piece 114 of the ventilation portion 112 on the second side 121 side of the flat tube insertion portion 113. The fin reinforcing portion 117 may have any one of the following structures: a convex structure having a convex shape of a circular arc, a convex structure having a convex shape with a corner, or a corrugated structure in which a plurality of the above shapes are arranged. The convex structure of the roof type is illustrated in fig. 3, but the shape of the fin reinforcing portion is not limited. Further, the fins 111 may be provided with a ridge structure, a convex structure, a corrugated structure, or the like in order to improve thermal conductivity, but these structures may be used as the fin reinforcing portion 117.

Effects of the embodiments

As described above, in the present embodiment, the cut-and-raised piece 114 is constituted by the portion corresponding to the notch residual portion C1 and the portion corresponding to the notch portion C2, the portion corresponding to the notch residual portion C1 being bent and cut upright on the first side 120 side of the flat tube insertion portion 113; the portion corresponding to the notch portion C2 is a portion of the ventilation portion 112 on the second side 121 side facing the first side 120, and is cut and raised together with the portion corresponding to the notch residual portion C1. Accordingly, regardless of the thickness of flat tube 11, even if the required fin pitch P is larger than the thickness of flat tube 11, cut-and-raised pieces 114 larger than the thickness of flat tube 11 can be formed on the inner peripheral edge of flat tube insertion portion 113. Therefore, it is possible to provide the heat exchanger 5 capable of securing the required fin pitch P larger than the thickness of the flat tubes 11.

Modification example

While the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. Several modifications will be described below, but the modifications are not limited to these, and these modifications can be combined within a reasonable range.

For example, in the fin 111 of the heat exchanger 5, the fin reinforcing portion 117 may be formed as a modification as shown in fig. 10 and 11. Fig. 10 shows an example in which the fin reinforcing portion 117 is formed along the shape of the notch portion C2. The mechanical strength of the fin 111 can be improved by providing the fin reinforcing portion 117 around the notch portion C2 having a reduced mechanical strength. Here, the fin reinforcing portion 117 is formed in an arc shape along the semicircular notch portion C2, but as described later, the notch portion C2 may be formed in a desired shape corresponding to the shape of the notch portion C2.

Fig. 11 shows an example in which the opposing surface 117a of the fin reinforcing portion 117 opposing the notch portion C2 is formed to be inclined in one direction with respect to the vertical direction. The notch C2, which is adjacent to and has a gap with the flat tube 11 inserted into the flat tube insertion portion 113, is likely to accumulate condensed water. However, when the condensed water adheres to the notch portions C2 to the fin reinforcing portion 117, the condensed water easily flows along the opposing surface 117a because the opposing surface 117a of the fin reinforcing portion 117 is inclined, and thus the drainage of the condensed water from the fins 111 is improved.

Further, in the fin 111 of the heat exchanger 5, the notched portion C2 may be formed as a modification as shown in fig. 12 and 13. Fig. 12 shows an example in which the notch C2 is cut away so that the inner peripheral edge has an acute angle θ. The acute angle θ is formed by, for example, a vertical side in the vertical direction and an inclined side inclined with respect to the vertical direction. The notch portion C2 is formed in a shape having the acute angle portion θ, so that condensed water accumulated in the notch portion C2 is concentrated at the acute angle portion θ, and the condensed water is easily discharged from the acute angle portion θ, whereby the drainage of condensed water from the fin 111 can be improved. Further, in this example, since the angle formed by the inclined side of the notch portion C2 and the second side 121 is reduced, the notch portion C2 can also function as a guide when the flat tube 11 is inserted into the flat tube insertion portion 113, and thus the ease of assembly of the heat exchanger 5 can be improved.

Fig. 13 shows an example in which an arc-shaped chamfer (R-chamfer) is formed at the boundary between the inner peripheral edge of the notch C2 and the second edge 121 of the flat tube insertion portion 113. Since the angle formed by the inner peripheral edge of the notch portion C2 and the second side 121 is reduced by not forming the corner at the boundary in this manner, the notch portion C2 can also function as a guide when the flat tube 11 is inserted into the flat tube insertion portion 113, and thus the ease of assembly of the heat exchanger 5 can be improved. In addition, a C-chamfer may also be formed at the interface.

Description of the symbols

1 air conditioner

2 indoor machine

3 outdoor machine

4 heat exchanger (indoor)

5 Heat exchanger (outdoors)

6 compressor

11 flat tube

111 fin, 111a first fin, 111b second fin

112 ventilation part (of fin)

113 Flat tube insert (Fin)

114 slice (of fin)

115 rising part (cut-and-raised piece)

116 fold back part (cut and raised piece)

117 fin reinforcing portion (of fin), 117a and reinforcing portion facing fin of notch portion facing each other

The C fin constitutes a cut-and-raised piece region, a C1 notch residual part (of the flat tube insertion part), a C2 notch part (of the ventilation part)

Length of W cut-and-raised piece (W1+ W2), length of W1C 1, length of W2C 2

P Fin Pitch, P1 Fin Pitch corresponding to C1, and P2 distance added by C2

Theta acute angle part (notched part)

R R chamfer (the boundary between the inner peripheral edge of the notch and the second edge of the flat tube insertion portion).

Claims

1. A heat exchanger, comprising:

a plurality of flat tubes stacked in a direction perpendicular to a flow direction of the refrigerant; and

a plurality of fins having a first flat tube among the plurality of flat tubes, a second flat tube adjacent to the first flat tube, a first flat tube insertion portion into which the first flat tube is inserted, and a second flat tube insertion portion into which the second flat tube is inserted, wherein,

a first fin of the plurality of fins is formed with a cut-and-raised piece for spacing a fin pitch between the first fin and an adjacent second fin at an inner peripheral edge of the first flat tube insertion portion,

the cut-and-raised piece has: a rising portion having the same length as the fin pitch; and a folded portion folded back at a front end of the standing portion and abutting against the second fin.

2. The heat exchanger of claim 1,

the first fin is provided with a fin reinforcing portion for improving rigidity of the fin on an inner peripheral edge side opposite to an inner peripheral edge on which the cut-and-raised piece stands in the first flat tube insertion portion.

3. The heat exchanger of claim 2,

the fin reinforcing part is of a raised structure, a protruding structure or a corrugated structure.